Navigant Research Blog

Utilities Nourish Smart Grids With Fiber

— August 14, 2013

Discussions of communications networks for smart grid initiatives tend to focus on private, radio-frequency (RF) mesh solutions in the United States, or narrowband-power line communications (N-PLC) in Europe and Asia.  As utilities look ahead to a truly integrated and robust smart grid, though, more and more demands will be placed upon the underlying communications network.  The need for high bandwidth, low latency, signal prioritization, and high security will only become greater over the course of the next decade.

At the same time, the integration of distribution automation (DA) applications with advanced metering infrastructure (AMI) is highlighting the limits of many AMI communications networks to support critical DA applications today. (For more on AMI/DA integration, see Navigant Research’s forthcoming report on Integrating Distribution Automation Applications with Advanced Metering Infrastructure.)  Limits, that is, unless the network is built upon fiber optics.

“Fiber-to-the-meter” isn’t a concept that many utilities talk about, primarily because of the very high cost of deploying fiber.  Passing a home with fiber can range from $700-$800 per home in densely populated areas to $4,000-$5,000 per home in lower density areas.  Despite the expense, a number of utilities in the U.S. have decided to deploy fiber to the meter—and their smart grids are among the smartest in the nation.

Generally speaking, municipal utilities have led the way in installing fiber optics, justifying the investment by offering a triple-play service (voice/video/data).  With consumers willing to spend upwards of $100 each month or more for triple-play services, the utility can justify the investment apart from the improved efficiency of its grid.

No Competition

Electric Power Board (EPB) in Chattanooga, Tennessee, is the largest such fiber-to-the-meter deployment in the U.S. to date, and the reported results have been impressive.  EPB’s 6,500-mile fiber network provides 5 millisecond (ms) speeds, enabling a full suite of DA applications, including automated self-healing and fault location, isolation, and service restoration (FLISR).

EPB reports that when remnants of Tropical Storm Lee hit Chattanooga in September 2011, even though its system was only about half deployed and less than 20% was automated, nearly one-third of homes and businesses in its service area avoided outage altogether or experienced less than a 2-second interruption, thanks to the automation built into the network.  In 2012, EPB’s average interruption duration index (SAIDI) fell 24% from 109 minutes to 82.5 minutes.  EPB also says its AMI applications are helping it avoid truck rolls and more easily verify restoration.  The robustness of fiber means that the number of applications the utility may now integrate is virtually unlimited—no other smart grid communications network today offers that kind of capacity (although 4G wireless may get there).

Unfortunately, fiber isn’t an option for all utilities today, and not only because of the costs.  Sixteen states have enacted legislation to prevent electric utilities from competing against franchised video service providers (cable and DBS); in other locales, the cable industry has filed lawsuits to stop the competition.  Without the monthly triple-play service revenue that fiber enables, many utilities will be unable to justify the expense.  Longer-term, cooperation among the cable, telecom, and utility industries might result in the ultimate in smart grid and robust communications and entertainment infrastructure—but that will no doubt require regulatory intervention.


Did the FCC Get it Wrong on Progeny?

— July 22, 2013

On June 6, the FCC issued an Order granting permission to Progeny LMS, LLC to begin commercial operation of its multi-lateral location and monitoring service (M-LMS) in the 900 MHz spectrum band.  Progeny’s system is expected to improve on existing location services like GPS by providing information on height – it can tell what floor a person is on in a high rise, for instance.  In addition to commercial applications, the service is intended for Enhanced 911 (E-911), which provides 911 operators with the physical location of the caller.  The company has received support from public safety agencies nationwide.

However, the utility industry is in an uproar.  Petitions for reconsideration were filed by seven entities last week, including Silver Spring Networks and the Part 15 Coalition (which includes companies like GE Digital Energy, Itron, Landis+Gyr, the UTC, and others).

The hubbub stems from the likelihood of interference with already deployed utility advanced metering infrastructure (AMI) and supervisory control and data acquisition (SCADA) systems, which operate in unlicensed 900 MHz spectrum.  Progeny uses licensed spectrum, and in granting the company permission to begin commercial operations, the commission made it clear that it placed Progeny’s business case (and potential E-911 benefits) ahead of the concerns raised by the utility industry.  In fact, the Part 15 system operators and devices are at the bottom of the heap when it comes to sharing spectrum in the lower 900 MHz band.


(Source:  FCC)

Unlicensed system operators are expected to make nice and engineer their systems so that signals can find alternate routes around interference – and for the most part, that’s what existing users have done.  The concern over Progeny’s system is that it is a high power system—30W—whereas most of the utility applications like AMI and SCADA are low power (from 1-3W).  Where interference develops, existing systems may have to be reconfigured, physically in some cases, and/or more hops may be required for a signal to reach its destination, increasing the latency of the data messages.

Safety Above All

Petitions for reconsideration point out that Progeny’s field tests – which were a requirement of the approval – didn’t test a wide-enough variety of devices.  In particular, they didn’t test against distribution SCADA systems that are dependent upon low latency.  Instead they tested only against AMI systems, which are less time-sensitive.  In its order, however, the FCC “concluded that the purpose of the field test is to promote the coexistence of M-LMS and unlicensed operations in the band by ‘minimizing’– not eliminating – the potential for M-LMS interference to Part 15 operations.”

The Order does require Progeny to work with other system operators to alleviate interference and also to report interference complaints to the Commission.  It also required Progeny to set up a  reporting website for interference issues and to report launched markets, which it did June 21.

A review of that list reveals that Progeny is already operational in 40 major markets covering two-thirds of the U.S. population.  “Operational” means that it has deployed equipment to cover at least one-third of the market.

Even before the order was adopted, PG&E filed ex parte comments with the commission describing SCADA interference that occurred at one of its sites in San Francisco last fall.  Based on how widely the Progeny system has already been deployed, such problems could soon arise in other cities.

The LMS spectrum license was originally established by the FCC in the mid-1990s, well before the widespread deployment of smart grid technology.  But in applying license conditions established nearly 20 years ago in its review of the Progeny situation, the commission appears to have been more motivated by the post-9/11 reverence for public safety than by smart energy goals.  In its petition for reconsideration, Silver Spring Networks asserts that “the Commission’s substantive rebalancing of the governing policies was peculiarly myopic, preferring a disappointingly modest improvement in E-911 services to a number of other important public policies, such as the reliability of critical infrastructure [and], amelioration of anthropogenic climate change.”


Wireless Networks Double-Edged for Utilities

— July 3, 2013

On June 25, President Obama announced new limits on carbon dioxide emissions from existing power plants.  While legal challenges are expected, the President has made it clear that implementing stricter greenhouse gas emissions limits is a top priority for his second term.  New restrictions on legacy power plants will take time to implement, but at the end of the day they will be far-reaching and expensive for utilities.

It was with this change ‑ and how smart grid efforts will factor in utility compliance ‑ in mind that I noted this SmartGridNews headline:  “Warning! Wireless Networks are Energy Monsters.”  Having recently written three Research Briefs on the use of wireless technology (LTE, WiMAX, and WiFi) for smart grid applications, I was surprised.  After all, better, cheaper, and more widespread wireless technology is helping to enable the smart grid, and that’s a good thing, right?

Turns out, it’s a double-edged sword.

Wireless networks are far less energy efficient than wired networks.  An article in the June 2011 issue of the IEEE Communications magazine headlined “Energy Consumption in Wired and Wireless Access Networks,” demonstrates a power consumption model comparing seven network technologies and forecasts the watts per user based on access rate.  While the wired technologies show relatively flat energy usage, regardless of the access rate, wireless technology like WiMAX and UMTS increase dramatically as access rates increase.

The explosive rise in global data traffic is also rapidly shifting from wired to wireless networks.  Combine these various trends, and, as the “Warning!” article referenced above notes, “The global telecommunications system is estimated to consume 2% of the world’s energy [today], and that figure could grow to 10% by 2020 if no action is taken to make it more energy efficient.”

Power Hogs

According to a study conducted by the Australia-based Centre for Energy Efficient Telecommunications (CEET), while there has been much focus on the energy consumption of proliferating data centers, driven by the spread of cloud computing, that the real energy hog is the wireless network itself.

CEET projects that the energy use of cloud services will grow 460% between 2012 and 2015, from 9 million MWh to between 32 MWh and 43 MWh, conservatively ‑ the equivalent of nearly 5 million new cars on the road.  Wireless access networks will be responsible for 90% of that energy.  In other words, the very networks that are enabling a smarter grid ‑ and the energy savings smart grids are meant to foster ‑ may actually make it harder for utilities to reduce their power consumption.

Fortunately, there is some good news.  Numerous efforts are underway by industry and vendors to reduce the power consumption of wireless networks.  One recent study suggested that communications networks could reduce energy consumption by 90% by 2020 if carriers take steps like deploying small cells, turning off cells during periods of low use, and sharing infrastructure.

Ultimately, utilities will have to incorporate renewable energy sources into their generation in order to reduce CO2 emissions.  But if burgeoning wireless networks also help them reduce power usage via smart grid applications, that’s good.  The fact that younger users are using ever more wireless capacity and energy to watch YouTube videos on their iPhones isn’t going to change, no matter what utilities do.  But the positives that real-time connectivity creates are dramatic, and the potential for energy-saving applications in the grid is just starting to be tapped.


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